HR not upholding a grievance against the company does not mean i did not have a grievance/issue. Of course i did.But if the grievance wasn't upheld, then this is evidence that there wasn't an issue which left you with no other option but to resign surely?
My grievance was answered 8 months after I submitted it.But the grievance had been answered no? It was just the appeal you were waiting on, but you did get an answer if I have read your thread correctly.